Notes

formal English variety of standard written English used to express abstract or sophisticated ideas as are found in research papers or literary criticism
general English written or spoken variety of standard English used by most educated speakers
gobbledygook formal, pretentious, wordy, redundant writing which uses abstract or technical terms inappropriately
idiom form of expression peculiar to a language or dialect and approved by usage; often has a meaning different from what the literal wording implies
informal English variety of standard English used in casual and intimate conversations, letters, etc
jargon specialized vocabulary of a particular trade, sect, or profession; also called shop talk.
nonstandard English English usage which has not gained widespread literary, cultural or social acceptance
slang colorful and eccentric language used by a particular social group; newly coined forms not yet accepted as informal idiom
standard English English usage which has gained literary, cultural, and social acceptance as appropriate for educated speakers